A Unix timestamp counts the seconds since 1 January 1970 at 00:00 UTC; many APIs and event streams send
milliseconds instead. epochDate converts seconds. For milliseconds, divide by 1,000 yourself.
Copy and paste
Seconds (10 digits today):
epochDate({Event Time})
Milliseconds (13 digits today):
epochDate(decimalToInt({Event Time Ms} / 1000))
A timestamp stored as text:
epochDate(parseInt({Event Time Text}))
Example
| Value | Unit | Formula | Result (UTC) |
|---|---|---|---|
| 1778803200 | seconds | epochDate(...) |
2026-05-15 00:00:00 |
| 1778851800 | seconds | epochDate(...) |
2026-05-15 13:30:00 |
| 1778851800123 | milliseconds | epochDate(decimalToInt(... / 1000)) |
2026-05-15 13:30:00 |
| 946684800000 | milliseconds | epochDate(decimalToInt(... / 1000)) |
2000-01-01 00:00:00 |
Why divide explicitly
The documentation says that epochDate discards the digits after the tenth when the integer is longer
than 10 digits. For a millisecond value from recent years (13 digits) that drops the last three and
gives the right second, so epochDate({Event Time Ms}) seems to work.
It fails for older values. Milliseconds before 9 September 2001 have 12 digits or fewer, and dropping
everything after the tenth digit then divides by 100, not 1,000. The value for 1 January 2000,
946684800000, would become 9466848000, a date in December 2269. Dividing by 1,000 is right for every
date. decimalToInt turns the quotient back into the integer that epochDate requires.
SPICE only
AWS documents epochDate for analyses based on SPICE datasets. For a direct-query dataset, convert in
the source query instead, for example from_unixtime(event_time) in Athena or TO_TIMESTAMP(event_time)
in Snowflake, so that the dataset already has a date column.
Time zone
The result is in UTC. To show local time, set the analysis time zone under Edit → Analysis
settings → Date and time → Convert time zone. QuickSight then converts the values, now() and
relative date filters at query time, and handles daylight saving time. Don’t add or subtract a fixed
number of hours in the formula: the offset changes twice a year.
Checked against the Amazon Quick Sight function reference (October 2026). The example results were recomputed in DuckDB.
